An adaptive voltage reference based multi-objective line flow control methods for MMC-MTDC system

• An advanced methodology is developed for DC line power flow regulation without extra power flow controllers. • A pre-evaluation method is proposed to evaluate the power transfer and available control variables. • A novel control strategy is proposed to develop dispatch solutions for the MTDC system connected to AC girds and wind farms. The regulation of DC line power flow and optimization of system operational characteristics after contingency is crucial for the stable and economic operation of the MTDC grid. In this paper, a novel adaptive voltage reference based multi-objective optimal control method is proposed for proper line power flow control, as well as voltage deviation minimization and economic operation of the MTDC system. A hierarchical control method based on the M-MOMPA algorithm is proposed for the development of dispatch solutions for the MTDC system connected to multiple AC systems and large-scale wind farms. A pre-evaluation method is proposed to choose appropriate control variables and accelerate the convergence of optimization algorithms. The effectiveness of the proposed approach is validated through comparisons with several algorithms. The dynamic simulations of a five-terminal MTDC grid are carried out using MATLAB/Simulink and RTLAB to verify the effectiveness of the proposed method under various types of disturbance and contingency.